Figure 2.

The structure and membrane topology of reticulons. (a) Structure of reticulon proteins. Numbers refer to the exons that encode the protein
regions. Black ovals represent hydrophobic regions. GenBank accession numbers are
as in Figure 1. (b) Possible topologies of reticulon proteins in membranes. Although eight or more conformations
are possible, only those for which evidence exists are depicted. Different topologies
in different cell types and different membranes may enable reticulons to carry out
diverse roles in the cell.